A Computer-Based Comparative Performance Analysis of QPSK and 4-QAM Schemes in Fading Channels [ READ ]
B. O. Omijeh and Sukubo
Amongst the industry trend of modulation schemes are the QPSK and QAM schemes. The 4QAM scheme is one of the categories of QAMs, and is an equivalent of the QPSK scheme in terms of number of information bits transmitted per symbol. In this research, not only are the two schemes compared in Rayleigh and Rician fading environment, comparison was also made to find out the BER performance differences of each scheme in the fading channels by applying SNR/BER as key performance indicator. With a design modeled in Simulink for this purpose, various instances of simulations were run and the resulting values of SNR/BER over different time period recorded for QPSK and 4QAM in the fading channels. By ensuring proper signal alignment and comparing the experimental product of SNR and BER with the theoretical expression SNR x BER = 1, the data set obtained and thus, the results are considered reliable. Findings show that 4QAM is generally a better modulation scheme but, is preferable in Rayleigh fading channel at the cost of transmission stability. It was also established that QPSK is an ideal choice in Rician environment than it is in Rayleigh fading environment
B. O. Omijeh and Sukubo
Amongst the industry trend of modulation schemes are the QPSK and QAM schemes. The 4QAM scheme is one of the categories of QAMs, and is an equivalent of the QPSK scheme in terms of number of information bits transmitted per symbol. In this research, not only are the two schemes compared in Rayleigh and Rician fading environment, comparison was also made to find out the BER performance differences of each scheme in the fading channels by applying SNR/BER as key performance indicator. With a design modeled in Simulink for this purpose, various instances of simulations were run and the resulting values of SNR/BER over different time period recorded for QPSK and 4QAM in the fading channels. By ensuring proper signal alignment and comparing the experimental product of SNR and BER with the theoretical expression SNR x BER = 1, the data set obtained and thus, the results are considered reliable. Findings show that 4QAM is generally a better modulation scheme but, is preferable in Rayleigh fading channel at the cost of transmission stability. It was also established that QPSK is an ideal choice in Rician environment than it is in Rayleigh fading environment
